Yarn stretching apparatus



May 5; 1959 HARGREAVES 2,884,679

I YARN STRETCHING APPARATUS Filed July 6, 1955 v 4 2 Sheets-Sheet 1 ROBERT HARGREAVES INVEN TOR.

" May 5, 1959 RHARGREAVES 2,884,679

YARN STRETCHING APPARATUS- Filed July 6, 1955 4 2 Sheets-Sheet z INVENTOR.

ROBERT HARGREAVE S Un a e Pat j t.0."3c

, .884. v YARN STRETCHI NG: APPARATUS Robert Hargreaves, Whitinsville, Mass, assignor' toWhltin Machine Works, Whitinsville, Mass 'a corporation of Massachusetts f,

Application July 6, 1955, Serial No. 520,252

(CLL ST Q This invention relates to apparatus forfstretching 'or'drafting yarn or cord or o er similar products made from fibrous material.

The usual stretching apparatus-comprises agfeed roll which is continuously rotatedat constant speed, and a drafting or stretching roll which is also continuou ly rotated but at a slightly higher peripheral speed. The peripheral speed ratio between the two rolls determines the draft or stretch.

The yarn is commonly given several turns around each of the rolls but yarn slippage at the feed roll nevertheless frequently occurs, with resultant uneven draft or stretch.

It is the general object of this invention to provide means for preventing such yam slippage on the feed roll, whereby substantially uniform stretch and yarn diameter may be attained. I also provide clear access to the feed roll for threading operations.

My invention further relates to arrangements and combi-nations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings, in which:

Fig. l is a partial front elevation of one form of the improved stretching apparatus;

Fig. 2 is a side elevation, looking in the direction of the arrow 2 in Fig. 1;

Fig. 3 shows a modified application of the improvement;

Fig. 4 shows another modified application;

Fig. 5 is an enlarged front elevation of a presser roll involving a locking device; and

Fig. 6 is a sectional side elevation, taken along the line 66 in Fig. 5.

Referring to Figs. 1 and 2, a portion of a yarn-stretching machine is shown as comprising a plurality of feed rolls 10 and drawing rolls 12 mounted in fixed bearings in a frame F and provided with driving shafts 14 and 15 (Fig. 2) which are continuously rotated from any convenient source of power.

All of the rolls are rotated at constant speed but the peripheral speed of the drawing rolls 12 is made somewhat greater than the peripheral speed of the feed rolls 10, whereby the desired draft or stretch is attained.

Separator rolls and 21 are provided for the feed rolls 10 and for the drafting rolls 12. These separator rolls 20 and 21 are mounted for free rotation on studs 22 (Fig. 2) in the frame F.

A separate strand or yarn Y is guided to each feed roll 10 through a yarn guide 24 and is delivered from the associated drafting roll 12 through a yarn guide 26.

Each yarn Y is given several turns around its feed roll 10 and its associated separator roll 20, as best indicated in Fig. 2. The yarn then passes to the drafting roll 12, where it is again given several turns around the roll 12 and its separator roll 21 before being delivered through a guide-wire 26.

1o 5 produced.

, 2,884,679 Patented May 5, .1959

The axes of the separator rolls 20 and 21 are preferably disposed at a slight angle to the axes of the feed rolls .10 and drafting rolls 12, so that the successiveturns of yarn Y on the various rolls will not overlap. The structure thus far described is in general of a common construction and commercially used.

' It has been found verydifficult to prevent. slippage of the yarn Y on the feed roll .10 and separator roll 20 when tension isapplied to. theyarn 'by the. drafting roll 12. When such slippage occurs, uneven 'yarn isinevitably To avoid this undesirable result, a presser roll 30 is mounted on air-arm 31 pivoted to swing freely about a fixed stud-32. Each prcsse'r roll 30 is-yieldingly pressed against its feed roll 10 by a torsion spring 34 (Fig. 6).

It is found that such yielding engagement of apresser roll 30'with a'feed'roll 10 is very effective and satisfactory in preventing slippage of the yarn Y- on the feed roll 10. -InFig. 1, the presser roll 30 isshown as engaging the under 'part'of the feed rol'1 .10, but a. presser-roll 30a (Fig. 3 )rnay be mountedon a fixed stud'32a and engage the side" of "the roll 10, era-feed roll 3% (Fig. 4) may be mounted on a fixed stud 32b and engage the top surface of the feed roll 10. In each of these positions, the torsion spring 34 forces the presser roll yieldingly against the feed roll.

The tension of the spring 34 must, however, be adjusted to suit the operating conditions. In Fig. 1, the spring must overcome the weight of the roll 30 and arm 31, while in Fig. 4 the weight of the roll 30b and arm 31b acts with the spring. In the construction shown in Fig. 3, the weight of the parts 30a and 31a is negligible.

Referring to Fig. 6, the stud 32a is secured in the frame F by a nut 40, and the arm 31a is loosely pivoted on the portion 41 of the stud 32a. Spring 34 is loosely mounted on the enlarged middle portion 42 of the stud 32a, and one end 34a of the spring 34 extends into an opening 42 in the arm 31a.

The other end 34b of the spring 34 extends into an opening 44 in a collar 45 mounted on the stud 32m and provided with a clamping screw 46. By turning the collar 45 on the stud 32, the tension of the spring 34 may be adjusted, and the desired tension may be retained by tightening the screw 46.

It is sometimes desirable to provide means to lock the presser roll 30a in withdrawn position to permit convenient threading of the machine. For this purpose, the locking structure shown in detail in Figs. 5 and 6 may be provided.

A plate 50 is welded or otherwise secured to the stud 32a supporting the arm 31a and the plate 50 is provided with arcuate slots 51 and 52 and the slot 51 has an enlarged end opening 53.

A stud 60 is mounted to slide in a transverse opening 61 in the arm 31a. The stud 60 has a reduced portion 62 slidable in the slot 51, and has an enlarged end portion 63 adapted to seat in the end opening 53 of the slot 51.

A spring collar 64 prevents displacement of the stud 60, and a spring 66 yieldingly forces the stud to the left as shown in Fig. 6.

For normal operation, the stud 60 is forced in against the spring 66 until the reduced portion 62 of the stud 60 can enter the slot 51 and until the enlarged outer end portion 63 can engage and slide along the outer surface of the plate 50.

The presser roll 30a will then be pressed against the feed roll 10 by the torsion spring 34 as previously described.

If it is desired to hold the roll 30a removed from the feed roll 10, as for re-threading, the presser roll 30a is swung away from the feed roll 10 until the enlarged end portion 63 of the stud 60 snaps into the enlarged end 3 portion 53 of the slot 51. The presser roll will then be locked in withdrawn position until the arm 31a is freed by inward pressure on the stud 60.

It will be understood that the structure shown in Figs. Sand i6-may be applied to feed rolls in anyone of the three positions indicated in Figs. 1, 3 and '4.

The winding or other disposal mechanism to which the yarn Y pa'ss'es from the guidewire '26commonlyiputs enough stress on the delivered yarn to prevent slippage on the drafting roll 12.

The locked-out position'o'f the -feed=roll is determined by :the angular position of the plate '50, which may be varied rby'turning the stud 32a to which his secured. The slot "52 :provides "clearance for the spring portion 34a. The spring tension may be adjusted, as stated, by turningthe collar 45.

Having thus described mytinvention and'the advantages thereof, 1 do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but whatt I claim is:

1. :In a yarn stretching apparatus :in which the yarn approaches and leaves the apparatus in a'single and substantially straight ,path, a continuously rotating feed roll, a continuously rotating drafting roll, a pressure roll engaging said feed roll, a swinging arm to support said pressure roll, a fixed stud on whichrsaid arm is mounted,

4 a coil spring on said stud having one end seated in said arm, a collar on said stud in which the other endof said spring is seated, and means to hold said collar in angularly adjusted position on said stud.

2. In a yarn stretching apparatus in which the yarn approaches and leaves the apparatus in a single and substantially straight path, a continuously rotating feed roll, a continuously rotating drafting roll, a pressure roll engaging said "fee-awn, spring means to apply pressure to said latter roll, means to adjust the pressure-applying spring tension, and positive means to hold said pressure roll away from said feed roll to facilitate threadingof the feed roll but retaining the adjusted operative spring tenslon.

References Cited in the file of this patent UNITED STATES PATENTS 2,402,228 .Jackson et al. a June 18, 1946 20 2,413,073 Saum Dec. 24, 1946 FOREIGN PATENTS 59,355 Netherlands May 16, 1947 68,684 Denmark Feb. 21, 1949 1,069,409 Franee Feb. 10, 1954 

